§ Origins
Processing MethodsProcess.
The processing method gives the same origin and variety completely different flavors.
Washed / Wet Process
ウォッシュド（水洗式）
Flavor tendency
Clean, bright acidity, floral, delicate flavors
One of the most common processing methods. The bean’s own terroir shows more than the fruit, with a clean, bright acidity. High consistency and few defective beans.
Process steps
- 1Soak harvested cherries in water and remove the floating defects
- 2Mechanically remove the skin and pulp (pulping)
- 3Ferment in tanks for 12–72 hours to break down remaining mucilage
- 4Wash with water and dry the parchment (2–4 weeks)
- 5Hull and mill into green beans
Main origins
It uses a lot of water, so the environmental load is a challenge. “Eco-washed” methods that cut water use have spread in recent years.
Natural / Dry Process
ナチュラル（乾燥式）
Flavor tendency
Fruity, wine, berry, sweetness, complex fermented character
The oldest processing method. Drying the cherry whole lets the fruit’s sugars and flavors soak into the bean. Wine-like fermentation and fruity sweetness are its hallmarks.
Process steps
- 1Spread harvested coffee cherries whole on drying beds
- 2Dry under direct sun for 3–6 weeks while fermenting
- 3Turn regularly for even drying
- 4After drying, hull to remove the skin and parchment
- 5Mill into green beans
Main origins
It uses no water, so it suits dry regions. But it’s harder to manage, with a risk of over-fermentation. Quality depends heavily on the producer’s skill.
Honey Process
ハニープロセス
Flavor tendency
Sweetness, syrupy mouthfeel, fruity, light fermented note
Midway between washed and natural. Flavor shifts from white (little mucilage) to black (lots). As the name suggests, a honey-like sweetness is the signature.
Process steps
- 1Remove the skin and pulp of harvested cherries (pulping)
- 2Dry with some or all of the mucilage left on
- 3Classify as white, yellow, red or black by how much is left
- 4Dry over 2–4 weeks
- 5Hull and mill into green beans
Main origins
More mucilage means stronger fermentation and sweetness (red/black honey). Less gives a washed-like cleanliness (white honey).
Wet-Hulled / Giling Basah
スマトラ式（ウェットハルド）
Flavor tendency
Earthy, spicy, heavy body, chocolate, herbal, low acidity
Indonesia’s own method. To cope with the hot, humid climate, the beans are hulled while semi-dry — a distinctive process. The beans turn blue-green, giving an earthy, full-bodied flavor.
Process steps
- 1After pulping, ferment overnight with the mucilage still on
- 2The next day, rinse and hull while still semi-dry (doing earlier what is usually done after drying)
- 3Dry 1–2 more days while still blue-green
- 4Dry to a final moisture content of 12–13%
- 5Re-sort before export
Main origins
Mandheling and Toraja coffees are processed this way. With low acidity and heavy body, it’s also used in espresso blends.
Anaerobic Fermentation
アナエロビック（嫌気性発酵）
Flavor tendency
Wine, fermentation, tropical fruit, complex, distinctive
An experimental method that has spread rapidly in specialty coffee recently. Fermentation is promoted in a sealed tank with oxygen excluded, producing complex, unique flavors unattainable with normal processing.
Process steps
- 1Place harvested cherries in a sealed tank
- 2Ferment for 12–200 hours with oxygen excluded
- 3Vent the CO2 produced during fermentation through a valve
- 4Dry by washed, natural or honey
- 5Mill into green beans
Main origins
Flavor varies greatly with fermentation time, temperature and cherry condition. Over-fermentation can produce a vinegary smell. A cutting-edge method that divides opinion.